The ex-banker was arrested in Turkey on Saturday and is being held in custody in Istanbul. According to state-run Athens-Macedonian News Agency, the Athens appeals prosecutor's office readied on Monday the necessary paperwork, which will be forwarded to Turkish authorities by the Justice Ministry.

It is not clear yet how long it will take for Filippidis to be sent back to Greece.

Former Hellenic Postbank vice-chairman Marios Varotsis became on Monday the first suspect to be questioned in connection to the probe into unsecured loans made by the lender.

Varotsis was arrested last week after the completion of an investigation into the bank’s activities.

A total of 25 people have been charged with fraud and money laundering in connection with the scandal miring TT, which issued half a billion euros in suspicious loans between 2007 and 2012, according to a prosecutor’s report.

The bulk of this – some 300 million euros in loans – was issued between the fall of 2008 and fall 2009, when Filippidis was at the lender’s helm, according to Bank of Greece inspectors.